An isometric hand tester: quantifying motor function in the hand

Area of Science:

• Rehabilitation Medicine
• Biomechanics
• Kinesiology

Background:

• Accurate measurement of hand muscle strength is crucial for diagnosing and managing various conditions.
• Existing methods for assessing hand strength may have limitations in specificity and reliability.
• Developing a dedicated isometric hand tester can provide a more precise evaluation tool.

Purpose of the Study:

• To develop and evaluate a novel isometric hand tester.
• To assess the reliability of the hand tester in measuring multiple strength parameters of hand muscles.
• To improve the measurement accuracy of intrinsic and extrinsic hand muscle strength.

Main Methods:

• Development of five distinct isometric tests: wrist flexion, wrist extension, metacarpophalangeal joint flexion, thumb adduction, and interphalangeal joint flexion.
• Inclusion of 19 men and 22 women in the initial study, followed by a second study with 17 men.
• Reliability assessment using the intraclass correlation coefficient (ICC) for single measures.

Main Results:

• High ICC values (greater than 0.9) were achieved when combining gender data for most tests.
• Tests for metacarpophalangeal joint flexion and thumb adduction showed slightly lower ICCs initially.
• Adjustments in the second study improved ICCs for metacarpophalangeal joint flexion and thumb adduction to between 0.70 and 0.83.

Conclusions:

• The newly developed isometric hand tester offers a reliable method for assessing hand muscle strength.
• The device effectively measures strength parameters for both intrinsic and extrinsic hand muscles.
• This tool has the potential to enhance clinical assessments and rehabilitation strategies for hand function.